All terrain vehicles ("ATV's") have become very popular for both recreational and utility purposes. ATV's are off-road vehicles characterized by having four wheels (two front and two rear) with low pressure tires, handlebars connected to the front wheels for steering, a straddle-type seat designed for a single rider, laterally extending footrests on opposite sides of the vehicle, and an engine and transmission located generally beneath the straddle-type seat and substantially between the footrests. Typically ATV's are not wider than about 50 inches--most commonly about 44-48 inches in overall width. The transmission typically is connected by a suitable drive train to the rear wheels. In many applications, it is desirable to have all four wheels driven by the engine. Four wheel drive ATV's typically have one drive train connecting the transmission to the rear wheels and a separate drive train connecting the transmission to the front wheels.
Two types of transmissions systems have been employed on ATV's: manual transmissions and continuously variable transmissions (CVT's). Most ATV manufacturers have historically used manual transmissions. The manually shifted transmission receives rotational power from the engine and, through gear reduction, provides that power to the drive wheels. Manual transmissions typically employ a conventional shifting clutch which can be activated by a handlebar-mounted hand operated lever or can be semi-automatically actuated by the shifting mechanism. The shift mechanisms of such manual transmissions typically employ a foot-operable shift lever located at a convenient position--usually on the left side of the vehicle a few inches in front of a laterally extending foot peg on which the rider rests the foot used to operate the lever.
A number of years ago the assignee of the present invention introduced the use of continuously variable transmissions (CVT's) on ATV's. CVT's typically employ a pair of split sheave clutches around which an endless belt is disposed. One of the clutches is connected to the output shaft of the engine, and the other clutch is connected to the input shaft of a gearbox. The CVT provides automatic and infinitely variable gear reduction from the output shaft of the engine to the input shaft of the gearbox, thus eliminating the need to shift the vehicle from one forward gear to the next as the vehicle accelerates. The gearbox is employed simply to shift from forward to neutral and reverse, as the CVT eliminates any need to shift among various forward gears. If desired, the gearbox may provide some additional gear reduction, and may include, e.g., an extra low forward gear for heavy pulling conditions. The gearbox is shifted by a hand operated lever when the vehicle is not moving.
Since the CVT eliminated the need for a foot-operated shift lever, it was possible for the assignee of the present invention to replace the foot pegs with full platform-style foot rests. Such footrests are shown, e.g., in U.S. Pat. No. D389,440. Each footrest provides a generally rectangular platform which is both longer and wider than the rider's foot. Each footrest also includes front and rear walls extending upwardly from the ends of the platform. Since each footrest is disposed between one of the front wheels and one of the rear wheels, the front wall of the footrest forms a part of the front fender, and the rear wall of the footrest forms a part of the rear fender.
Manufacturers of ATV's utilizing manual transmissions shifted by a foot-operated shift lever have occasionally attempted to increase the protection for a rider's foot by providing a footrest larger than the traditional foot peg. For example, U.S. Pat. No. 4,768,799 shows a footguard which can be retrofitted onto an ATV with a conventional foot peg/shift lever system. The footguard includes a generally rectangular metal frame extending around the area of the foot peg and shift lever, and includes a plate on which the rider may rest his heel. To permit the required up and down movement of the shift lever, however, the pad of the shift lever (i.e., the portion of the shift lever engaged by the rider's foot) is generally centered in a large opening in the footguard--the opening being sufficiently large for the rider to insert his foot through the opening (this being necessary to permit the operator to push the lever upward to upshift the manual transmission).